In a manufacturing process of, e.g., a semiconductor device, various processes such as an ion implanting process, an etching process and a film forming process are performed on a substrate. When performing these processes, a so-called multi-chamber type substrate processing system having a plurality of processing apparatuses is used in order to achieve consistency, connectivity or integration of the processes.
Installed in the multi-chamber type substrate processing system are a substrate accommodation vessel that receives, in a height direction, a plurality of substrates loaded or unloaded into/from the processing apparatus and a transfer apparatus that transfers the substrates between the processing apparatus and the substrate accommodation vessel. The transfer apparatus has a transfer arm capable of revolution, expansion/contraction or elevation, so that a substrate holder of the transfer arm can take out or put in a single sheet of substrate at each height by accessing an opening of the substrate accommodation vessel. Further, the substrate holder can load and unload each substrate into/from the processing apparatus installed opposite to the substrate accommodation vessel across the transfer apparatus by accessing the processing apparatus.
However, when replacing a processed substrate with an unprocessed substrate in such a substrate processing system, the processing apparatus is in a standby state, i.e., in a non-operating state. Therefore, in order to improve throughput of the substrate processing system, it is important to reduce time required for transferring a substrate between the processing apparatus and the substrate accommodation vessel or time required for changing the substrates in the processing apparatus. Conventionally, as disclosed in, for example, Patent Document 1, a loading arm for loading a substrate and an unloading arm for unloading a processed substrate from a processing apparatus are separately and independently installed, and, thus, the loading arm can load an unprocessed substrate to a processing apparatus' empty space from which the unloading arm has just unloaded a substrate. In this way, since the loading arm and the unloading arm are independently installed, it is possible to reduce time required for changing substrates in a processing apparatus, in particular, in a batch-type processing apparatus capable of performing a batch process on a plurality of substrates, whereby throughput can be improved.
Patent Document 1: Japanese Patent Laid-open Publication No. H3-254119